Introduction

There are three main types of steel that we work with as blacksmiths and bladesmiths, Mild steel, carbon steel, and stainless steel.

Mild steel generally comes in two grades, A36 and 1018, with 1018 being the purer of the two. Mild steel is readily available at stores and steel suppliers, but it doesn't have enough carbon to harden, making it unsuitable for knife steel.

Carbon Steel is the term we use for steel with carbon contents between 0.4% and 1.5% carbon, with most knife steels being between the .7% and 1.2% range.

The third type is stainless steel, containing a minimum of 10.5% chromium. It's available in martensitic and austenitic as well as hardenable and non-hardenable forms. Since we want to talk about steel blacksmiths and bladesmiths commonly use, we'll focus on carbon steel.

1080

1080 is a "simple" high carbon steel, one of our favorites due to its ease of use and high-performance. We use 1080 in our Damascus-steel as the dark layers in the pattern. Due to its forgiving nature, 1080 is a favorite for beginner knifemakers and bladesmiths; however, it offers a performance level high enough that it is still commonly used by master smiths.

The carbon content of steel is 0.8%, right in the sweet spot for many different applications. It has quite a generous window of forgeable temperatures; it doesn't mind going up to a high yellow while being welded together and doesn't stress fracture easily in the 1500°F (816°C) degree range.

15n20

15n20 is a high carbon, high nickel alloy steel; it is extremely tough and versatile. We choose 15n20 to pair with 1080 for our Damascus steel, it makes up the bright layers in the pattern, as the nickel in the steel resists the ferric-chloride we use to etch blades.

It has a carbon content of 0.75% and moves similarly to 1080 while having a different heat treatment and final hardness. The alloying of nickel in 15n20 brings a little extra toughness and allows it to take a keener edge than many other types of high-carbon steel.

L-6

L-6 is a high nickel content steel ideal for tools that need extreme toughness such as swords, big knives, axes, and other tools that need to hold up in high-stress situations. It has a more particular forging temperature range than other steels like 1080 and 15n20, it's not able to be forged as hot or as cold as those more forgiving steels.

4140

4140 is a type of Chromium-molybdenum mid-carbon steel, often used in industry for anything that needs more strength than mild steel. It's preferable for industrial applications such as shafting, axles, tooling, etc. For blacksmiths, this is usually for hard use tools that don't require fine edge retention.

4340

4340 is a beefed-up version of 4140, with a higher nickel content than 4140; it has improved edge retention and performs better under high heat. 4340 is the steel we choose to make our hammer eye drifts from, and it is an excellent choice for similar tooling in the blacksmith/ bladesmith setting.

1045

1045 is a simple mid-carbon alloy, and it is our choice for hammer steel, as it has the right blend of hardness and toughness. It is a little soft to make a good axe, knife, or sword, but for non-edged tools where simple and consistent forging and heat treatment is required, it is often a fantastic option. 

H-13

H13 is a hot working tool steel, meaning it resists deformation when brought to high temperatures, such as when punching or shaping hot steel in various operations. It is the industry standard for hot punches, drifts, and dies.

H13 significantly more robust than other steels to forge, and care should be taken with heat treatment as it is air-hardening steel. Incorrect use of this steel can result in the tool you make chipping or damaging other tooling and potentially causing injury.